package com.whut.customer.shiro;

import org.apache.commons.lang3.StringUtils;
import org.apache.shiro.web.servlet.ShiroHttpServletRequest;
import org.apache.shiro.web.session.mgt.DefaultWebSessionManager;
import org.apache.shiro.web.util.WebUtils;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import java.io.Serializable;

/**
 * 自定义session管理
 *  <br/>
 *  传统结构项目中，shiro从cookie中读取sessionId以此来维持会话，在前后端分离的项目中（也可在移动APP项目使用），
 *  我们选择在ajax的请求头中传递sessionId，因此需要重写shiro获取sessionId的方式。
 *  自定义MySessionManager类继承DefaultWebSessionManager类，重写getSessionId方法
 *
 */
public class CustomSessionManager extends DefaultWebSessionManager {

    private static final String AUTHORIZATION="Authorization";

    private static final String REFERENCED_SESSION_ID_SOURCE ="Stateless request";

    @Override
    protected Serializable getSessionId(ServletRequest request, ServletResponse response){
        String id= WebUtils.toHttp(request).getHeader(AUTHORIZATION);
        // 如果请求头中有Authorization，则其值为sessionId
        if(!StringUtils.isEmpty(id)){
            request.setAttribute(ShiroHttpServletRequest.REFERENCED_SESSION_ID_SOURCE,REFERENCED_SESSION_ID_SOURCE);
            request.setAttribute(ShiroHttpServletRequest.REFERENCED_SESSION_ID,id);
            request.setAttribute(ShiroHttpServletRequest.REFERENCED_SESSION_ID_IS_VALID,Boolean.TRUE);
            return id;
        }
        else{
            // 否则按照默认规则从cookie取sessionId
            return super.getSessionId(request,response);
        }
    }

}
